#!/bin/sh

#
# SPDX-License-Identifier: BSD-2-Clause-FreeBSD
#
# Copyright (c) 2018 Dell EMC Isilon
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#

# Parallel unmount of the same mount point with one mounter thread and 4
# threads doing unmount.

# "panic: dounmount: invalid lock refcount in the drain path @
# ../../../kern/vfs_mount.c:1409" seen in WiP code.

[ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1

. ../default.cfg

parallel=4
continue=/tmp/umount3.cont
touch $continue

[ -c /dev/md$mdstart ] && mdconfig -d -u $mdstart
mdconfig -a -t swap -s 10m -u $mdstart || exit 1
newfs $newfs_flags md$mdstart > /dev/null
mount /dev/md$mdstart $mntpoint

for i in `jot $parallel`; do
	while [ -f $continue ]; do umount $mntpoint; done 2>/dev/null &
done

start=`date '+%s'`
while [ $((`date '+%s'` - start)) -lt 300 ]; do
	mount | grep -q "on $mntpoint " ||
	    mount /dev/md$mdstart $mntpoint
done > /dev/null 2>&1
rm $continue
wait

while mount | grep $mntpoint | grep -q /dev/md; do
	umount $mntpoint || sleep 1
done
mdconfig -d -u $mdstart
exit 0